Answer :
Answer:
Tom paints the fence in 24 hours and Bill paints the fence in 12
Step-by-step explanation:
T = 1 fence / x hours
B = 1 fence / x - 12 hours
B + T = 1 fence / 8 hours
( 1 fence / x - 12 hours ) + ( 1 fence / x hours ) = 1 fence / 8 hours
( 1 / x - 12 ) + ( 1 / x ) = 1 / 8
multiply through all the denominators to get:
8x + 8 (x - 12 ) = x( x - 12 )
8x + 8x - 96 = x^2 - 12x
combine like terms to get:
x^2 - 28x + 96 = 0
factor to get:
( x - 4 ) ( x - 24 ) = 0
x = 4, 24
4 won't work, because that would mean Bill would take a negative amount of time to paint the fence by himself, so that means
Tom paints the fence in 24 hours and Bill paints the fence in 12